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Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -07001/*
2 * An rtc driver for the Dallas DS1742
3 *
4 * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -08009 *
10 * Copyright (C) 2006 Torsten Ertbjerg Rasmussen <tr@newtec.dk>
11 * - nvram size determined from resource
12 * - this ds1742 driver now supports ds1743.
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070013 */
14
15#include <linux/bcd.h>
16#include <linux/init.h>
17#include <linux/kernel.h>
18#include <linux/delay.h>
19#include <linux/jiffies.h>
20#include <linux/rtc.h>
21#include <linux/platform_device.h>
22#include <linux/io.h>
23
Atsushi Nemotoac18eb62009-12-15 16:46:02 -080024#define DRV_VERSION "0.4"
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070025
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -080026#define RTC_SIZE 8
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070027
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -080028#define RTC_CONTROL 0
29#define RTC_CENTURY 0
30#define RTC_SECONDS 1
31#define RTC_MINUTES 2
32#define RTC_HOURS 3
33#define RTC_DAY 4
34#define RTC_DATE 5
35#define RTC_MONTH 6
36#define RTC_YEAR 7
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070037
38#define RTC_CENTURY_MASK 0x3f
39#define RTC_SECONDS_MASK 0x7f
40#define RTC_DAY_MASK 0x07
41
42/* Bits in the Control/Century register */
43#define RTC_WRITE 0x80
44#define RTC_READ 0x40
45
46/* Bits in the Seconds register */
47#define RTC_STOP 0x80
48
49/* Bits in the Day register */
50#define RTC_BATT_FLAG 0x80
51
52struct rtc_plat_data {
53 struct rtc_device *rtc;
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -080054 void __iomem *ioaddr_nvram;
55 void __iomem *ioaddr_rtc;
56 size_t size_nvram;
57 size_t size;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070058 unsigned long last_jiffies;
Torsten Ertbjerg Rasmussen3a729702009-06-17 16:26:07 -070059 struct bin_attribute nvram_attr;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070060};
61
62static int ds1742_rtc_set_time(struct device *dev, struct rtc_time *tm)
63{
64 struct platform_device *pdev = to_platform_device(dev);
65 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -080066 void __iomem *ioaddr = pdata->ioaddr_rtc;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070067 u8 century;
68
Adrian Bunkfe20ba72008-10-18 20:28:41 -070069 century = bin2bcd((tm->tm_year + 1900) / 100);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070070
71 writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
72
Adrian Bunkfe20ba72008-10-18 20:28:41 -070073 writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR);
74 writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH);
75 writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
76 writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE);
77 writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS);
78 writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES);
79 writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070080
81 /* RTC_CENTURY and RTC_CONTROL share same register */
82 writeb(RTC_WRITE | (century & RTC_CENTURY_MASK), ioaddr + RTC_CENTURY);
83 writeb(century & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
84 return 0;
85}
86
87static int ds1742_rtc_read_time(struct device *dev, struct rtc_time *tm)
88{
89 struct platform_device *pdev = to_platform_device(dev);
90 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -080091 void __iomem *ioaddr = pdata->ioaddr_rtc;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -070092 unsigned int year, month, day, hour, minute, second, week;
93 unsigned int century;
94
95 /* give enough time to update RTC in case of continuous read */
96 if (pdata->last_jiffies == jiffies)
97 msleep(1);
98 pdata->last_jiffies = jiffies;
99 writeb(RTC_READ, ioaddr + RTC_CONTROL);
100 second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
101 minute = readb(ioaddr + RTC_MINUTES);
102 hour = readb(ioaddr + RTC_HOURS);
103 day = readb(ioaddr + RTC_DATE);
104 week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
105 month = readb(ioaddr + RTC_MONTH);
106 year = readb(ioaddr + RTC_YEAR);
107 century = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
108 writeb(0, ioaddr + RTC_CONTROL);
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700109 tm->tm_sec = bcd2bin(second);
110 tm->tm_min = bcd2bin(minute);
111 tm->tm_hour = bcd2bin(hour);
112 tm->tm_mday = bcd2bin(day);
113 tm->tm_wday = bcd2bin(week);
114 tm->tm_mon = bcd2bin(month) - 1;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700115 /* year is 1900 + tm->tm_year */
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700116 tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700117
118 if (rtc_valid_tm(tm) < 0) {
119 dev_err(dev, "retrieved date/time is not valid.\n");
120 rtc_time_to_tm(0, tm);
121 }
122 return 0;
123}
124
David Brownellff8371a2006-09-30 23:28:17 -0700125static const struct rtc_class_ops ds1742_rtc_ops = {
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700126 .read_time = ds1742_rtc_read_time,
127 .set_time = ds1742_rtc_set_time,
128};
129
Zhang Rui91a69022007-06-09 13:57:22 +0800130static ssize_t ds1742_nvram_read(struct kobject *kobj,
131 struct bin_attribute *bin_attr,
132 char *buf, loff_t pos, size_t size)
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700133{
Atsushi Nemoto50e49be2009-12-15 16:46:04 -0800134 struct device *dev = container_of(kobj, struct device, kobj);
135 struct platform_device *pdev = to_platform_device(dev);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700136 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -0800137 void __iomem *ioaddr = pdata->ioaddr_nvram;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700138 ssize_t count;
139
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -0800140 for (count = 0; size > 0 && pos < pdata->size_nvram; count++, size--)
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700141 *buf++ = readb(ioaddr + pos++);
142 return count;
143}
144
Zhang Rui91a69022007-06-09 13:57:22 +0800145static ssize_t ds1742_nvram_write(struct kobject *kobj,
146 struct bin_attribute *bin_attr,
147 char *buf, loff_t pos, size_t size)
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700148{
Atsushi Nemoto50e49be2009-12-15 16:46:04 -0800149 struct device *dev = container_of(kobj, struct device, kobj);
150 struct platform_device *pdev = to_platform_device(dev);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700151 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -0800152 void __iomem *ioaddr = pdata->ioaddr_nvram;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700153 ssize_t count;
154
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -0800155 for (count = 0; size > 0 && pos < pdata->size_nvram; count++, size--)
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700156 writeb(*buf++, ioaddr + pos++);
157 return count;
158}
159
Prarit Bhargavac2391222007-02-12 00:52:29 -0800160static int __devinit ds1742_rtc_probe(struct platform_device *pdev)
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700161{
162 struct rtc_device *rtc;
163 struct resource *res;
164 unsigned int cen, sec;
Atsushi Nemotoac18eb62009-12-15 16:46:02 -0800165 struct rtc_plat_data *pdata;
166 void __iomem *ioaddr;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700167 int ret = 0;
168
169 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
170 if (!res)
171 return -ENODEV;
Atsushi Nemotoac18eb62009-12-15 16:46:02 -0800172 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700173 if (!pdata)
174 return -ENOMEM;
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -0800175 pdata->size = res->end - res->start + 1;
Atsushi Nemotoac18eb62009-12-15 16:46:02 -0800176 if (!devm_request_mem_region(&pdev->dev, res->start, pdata->size,
177 pdev->name))
178 return -EBUSY;
179 ioaddr = devm_ioremap(&pdev->dev, res->start, pdata->size);
180 if (!ioaddr)
181 return -ENOMEM;
182
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -0800183 pdata->ioaddr_nvram = ioaddr;
184 pdata->size_nvram = pdata->size - RTC_SIZE;
185 pdata->ioaddr_rtc = ioaddr + pdata->size_nvram;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700186
Torsten Ertbjerg Rasmussen3a729702009-06-17 16:26:07 -0700187 pdata->nvram_attr.attr.name = "nvram";
188 pdata->nvram_attr.attr.mode = S_IRUGO | S_IWUSR;
189 pdata->nvram_attr.read = ds1742_nvram_read;
190 pdata->nvram_attr.write = ds1742_nvram_write;
191 pdata->nvram_attr.size = pdata->size_nvram;
192
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700193 /* turn RTC on if it was not on */
Torsten Ertbjerg Rasmussenf9231a02006-12-06 20:39:41 -0800194 ioaddr = pdata->ioaddr_rtc;
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700195 sec = readb(ioaddr + RTC_SECONDS);
196 if (sec & RTC_STOP) {
197 sec &= RTC_SECONDS_MASK;
198 cen = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
199 writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
200 writeb(sec, ioaddr + RTC_SECONDS);
201 writeb(cen & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
202 }
Atsushi Nemoto391b1fe2006-09-30 23:28:18 -0700203 if (!(readb(ioaddr + RTC_DAY) & RTC_BATT_FLAG))
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700204 dev_warn(&pdev->dev, "voltage-low detected.\n");
205
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700206 pdata->last_jiffies = jiffies;
207 platform_set_drvdata(pdev, pdata);
Atsushi Nemotoac18eb62009-12-15 16:46:02 -0800208 rtc = rtc_device_register(pdev->name, &pdev->dev,
209 &ds1742_rtc_ops, THIS_MODULE);
210 if (IS_ERR(rtc))
211 return PTR_ERR(rtc);
212 pdata->rtc = rtc;
Torsten Ertbjerg Rasmussen3a729702009-06-17 16:26:07 -0700213
214 ret = sysfs_create_bin_file(&pdev->dev.kobj, &pdata->nvram_attr);
215 if (ret) {
216 dev_err(&pdev->dev, "creating nvram file in sysfs failed\n");
Atsushi Nemotoac18eb62009-12-15 16:46:02 -0800217 rtc_device_unregister(rtc);
Torsten Ertbjerg Rasmussen3a729702009-06-17 16:26:07 -0700218 }
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700219 return ret;
220}
221
222static int __devexit ds1742_rtc_remove(struct platform_device *pdev)
223{
224 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
225
Torsten Ertbjerg Rasmussen3a729702009-06-17 16:26:07 -0700226 sysfs_remove_bin_file(&pdev->dev.kobj, &pdata->nvram_attr);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700227 rtc_device_unregister(pdata->rtc);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700228 return 0;
229}
230
231static struct platform_driver ds1742_rtc_driver = {
232 .probe = ds1742_rtc_probe,
233 .remove = __devexit_p(ds1742_rtc_remove),
234 .driver = {
Atsushi Nemotoa95e23a2007-10-16 01:28:18 -0700235 .name = "rtc-ds1742",
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700236 .owner = THIS_MODULE,
237 },
238};
239
240static __init int ds1742_init(void)
241{
242 return platform_driver_register(&ds1742_rtc_driver);
243}
244
245static __exit void ds1742_exit(void)
246{
Atsushi Nemotoef154ec2007-07-21 04:37:55 -0700247 platform_driver_unregister(&ds1742_rtc_driver);
Atsushi Nemoto5ec3e4b2006-06-25 05:48:29 -0700248}
249
250module_init(ds1742_init);
251module_exit(ds1742_exit);
252
253MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
254MODULE_DESCRIPTION("Dallas DS1742 RTC driver");
255MODULE_LICENSE("GPL");
256MODULE_VERSION(DRV_VERSION);
Kay Sieversad28a072008-04-10 21:29:25 -0700257MODULE_ALIAS("platform:rtc-ds1742");